Hi, We're taking an Alaskan cruise in August and I'm in a quandary as to what gear to take. The land portion of the cruise will require that we lug all our valuables with us during the day while the cruise line moves our other luggage from point to point. The dilemma is whether to take a heavy long zoom and lug it around or go with a shorter focal length that is lighter weight. I've never been on one of these cruises, so I don't know how close we will be to wildlife and other photo ops that would benefit from the long zoom. Current plans are to take a Nikon D5500, 18-200 DX zoom, and a 70-300 zoom. The IQ with these lenses is acceptable at medium focal lengths but deteriorates at the longest. I'm prepared to buy the Nikkor 200-500 (or possibly rent it), but it weighs nearly 5 pounds. Has anyone been on a similar trip who can offer some insight? Thanks.